A surgical scrub brush of the general type here contemplated is known from U.S. Pat. No. 3,447,181 to Coker et al. According to that patent, an injection-molded brush body comprises a set of bristles integral with a U-shaped backing which may be used as a handle. A sponge of open-cell polyurethane foam is bonded onto the backing, on the side opposite the bristles, and is impregnated with surgical detergent. The patentees mention polyethylene as the preferred material for molding the brush body.
It is also known to provide a detergent-impregnated pad with bristles directly projecting from one of its major surfaces; see U.S. Pat. No. 3,392,421 to Mathison.
In commonly owned U.S. patent application Ser. No. 309,041 filed Sept. 28, 1981 by Joseph Vallis, now abandoned and replaced by application Ser. No. 445,856 filed Dec. 1, 1982 there has been disclosed a disposable brush for surgical purposes wherein a bristle-carrying base element or handle portion forms a compartment for soap, the base element having perforations through which dissolved soap may pass to the bristles to form suds. That application also teaches the use of a thermoplastic rubber, specifically a styrene/butadiene copolymer available under the trademark KRATON, as the preferred material for the brush body whose interaction with the soap has been found to promote foaming.
Two earlier patents by the same Joseph Vallis, U.S. Pat. Nos. 3,744,078 and 3,843,991, disclose and claim a nail brush whose bristles are of different lengths so as to define a cleaning face with a longitudinal groove and transverse depressions, the groove accommodating the tip of a finger whose nail is to be cleaned. The bristles are described as consisting of a synthetic plastic material which may or may not be the same as that used for their backing element.